This post is a real quick tip, but I have been using it lately to geneate all sorts of cool percussion patterns and grooves. If you are stuck for rhythmic ideas, or just want to add some variety to a simple drum loop, try sending some drums or percussion through an Alligator Triple Filtered Gate. Here what I will typically do:

Create a ReDrum

Right click on the Redrum and from the pop up menu choose Creative FX -> Alligator Triple Filtered Gate.

Click on the Redrum, then choose Edit -> Randomize Pattern.

Press Play on the Redrum.

Try turning down the Delay on the Alligator and using patterns in the 30's and above. You can make some cool grooves. Here I am just experimenting with different patterns layered on top of a basic rock beat.

And here is the Reason 6 Song file so you can see how it is all set up. Happy filtering!